1. Field of the Invention
The invention relates in particular to a medical handpiece.
2. Description of Related Technology
A handpiece of this kind is described in DE 44 06 855 A1. In the case of this previously known handpiece, a collet chuck is arranged in the front end region of a hollow drive shaft and is connected on the rear side to a draw rod, for the compression of the collet chuck, which at the same time is a longitudinal section of the drive shaft. The draw rod is formed by a pressure spring that is arranged between it and the hollow drive shaft in the form of a helical spring that is stayed with its front end at a shoulder of the hollow drive shaft directed towards the rear and acts with its rear end on a shoulder of the draw rod directed towards the front and thus pretensions the draw rod towards the rear. In this connection, the drive shaft in the region of the pressure spring consists of two sleeve-shaped portions that are extended in terms of their cross-sectional size with regard to the other axial sections of the drive shaft and overlap each other and are fixedly connected together. In the case of this known development, a complicated construction emerges that not only results in large cross-sectional dimensions, but also presupposes expensive assembly and disassembly.